Write/compare against expectations in skimage tool.

skimage:
Add two new modes: one to write expectations to a json file, and
another to compare results against expectations.
Use SkPATH_SEPARATOR instead of '/'.

gm_expectations:
Split into a static library so it can be used by skimage.
Make functions non static and move function definitions into source
file.
Capitalize static member functions to follow the coding style
guidelines.

BUG=https://code.google.com/p/skia/issues/detail?id=1241
R=epoger@google.com

Review URL: https://codereview.chromium.org/14670021

git-svn-id: http://skia.googlecode.com/svn/trunk/gyp@9069 2bbb7eff-a529-9590-31e7-b0007b416f81
2 files changed